1. Field of the Invention
The present invention relates to a status management system that manages and notifies status information of presentity. The status management system includes a presence server and a plurality of clients. The presence server stores the status information (hereinafter referred to as presence information) receives from any given client C1, and distributes it to other clients C2.
Presentity is a client that possesses presence information. Watcher is a destination client to which presence information of a presentity is distributed. Buddy is a presentity that provides its presence information for a watcher. Publisher is a client that updates presence information of a presentity other than itself. It does not matter whether or not a presentity allows the publisher to update its presence information.
2. Related Art
In anticipation of a coming ubiquitous society, a status management system has been proposed in which presence information of a presentity is updated by a client other than itself, namely, a publisher. In order to achieve the above mentioned system, publisher B that updates presence information of presentity A must obtain permission for updating presence information of presentity A in advance. A presence server stores, for each presentity, one or more publishers that are allowed by a presentity to update presence information thereof. Therefore, only the presence information updated by the allowed publisher B is stored as presence information of presentity A. Presence information updated by publisher C that is denied for updating by presentity A or presence information updated by publisher D that is neither allowed nor denied for updating by presentity A will not be stored as presence information of presentity A.